As a rebellious teenager, I went through an Aleister Crowley phase. I was convinced that the black magic expert known as “the wickedest man in the world” was a prophet before his time with an important message for mankind. At one point, a friend and I decided to sacrifice a chicken in Crowley’s honour, but after chasing it around a field for half an hour we thought better of it.

It’s a pity this biography of Crowley by Tobias Churton wasn’t available back then since it would have instantly cured me of this fascination. Churton intends his book to be a corrective to The Great Beast, an earlier biography by John Symonds which portrayed Crowley as a larger-than-life villain who defiled virgins and corrupted young men. Not so, says Churton.

“Crowley’s reputation has been distorted by history,” he writes. “This biography aims to correct the distortion, establishing recognition of Crowley as a major thinker, as significant as Freud or Jung.”

Problem is, the Crowley of legend – drug addict, sex fiend, traitor – is much more interesting than the harmless eccentric who emerges in the pages of this book. Indeed, Crowley doesn’t seem like a “major thinker” so much as a comic figure, the creation of a gifted Victorian satirist. Reading of his earnest attempts to invoke various pagan deities and his initiation into the “Sacred Magic of Abra-Melin the Mage”, it’s difficult not to laugh.

This was the conclusion reached by the poet GK Chesterton when he reviewed some of Crowley’s early poetry: “To the side of a mind concerned with idle merriment there is certainly something a little funny in Mr Crowley’s passionate devotion to deities who bear such names as Mout and Nuit, and Ra and Shu, and Hormakhou.”

Tobias Churton doesn’t help his cause by being incapable of writing in plain English. For instance, when discussing the end of Crowley’s time at Cambridge he writes: “Disdaining to barter intellect for a paid career, Crowley had eschewed final examinations at Trinity.” What he means (I think) is that Crowley failed to turn up for his exams.

Churton’s other major shortcoming is that he believes in the same occultist mumbo jumbo as his subject. He takes almost all Crowley’s outlandish claims in his personal diaries as gospel truth, whether it’s wrestling with vampires on the “astral plane”, experimenting with “invisibility” in Cairo or dispatching Beelzebub to eliminate a love rival in Moscow. It’s as if someone came across a copy of Harry Potter and the Philosopher’s Stone and mistook it for a work of non-fiction.

This doesn’t inspire much confidence in Churton as a forensic investigator. One of the Crowley myths he attempts to debunk is that he sided with the Germans during the First World War. Churton acknowledges that Crowley wrote for various anti-British propaganda sheets while living in New York at the time, but claims this was to gain the confidence of German fifth columnists so he could then spy on them more effectively. But the evidence for this is threadbare, at best, and relies on taking Crowley’s own post-hoc rationalisations at face value.

Churton is on safer ground documenting Crowley’s litany of sexual conquests. The photographs of the Beast in the book make him look rather shifty – a non-camp version of Stephen Fry – but he appears to have had a mesmerising affect on the opposite sex. He steadily worked his way through a horde of star-struck lovers, most of them respectable, married women. Perhaps they were intrigued by his talk of “sex magick”, a form of devil worship that involved energetic lovemaking.

On coming to the end of the book, I was surprised to learn that Crowley had only sired two children – or, at least, only two that we know of. Perhaps that’s just as well, given the ridiculous names he gave them. He dubbed his first born Nuit Ma Ahathoor Hecate Soppho Jezebel Lilith Crowley.

All in all, this biography is rather a disappointing addition to the anals of Crowleyana. Churton should have followed the advice of the newspaper editor in The Man Who Shot Liberty Valance: “When the legend becomes fact, print the legend.”